Chain driven reciprocating hammer with automatic work piece input centering and clamping

ABSTRACT

The Chain Drive Reciprocating Hammer is an apparatus for driving pile, poles pipe etc. that uses a chain lifting system to raise a ram to a predetermined height where the ram is released to free fall. The energy of the pull of gravity is applied to the driving of pile, poles, pipe etc. when the free falling ram strikes the pile, pole, pipe etc. Said apparatus has a mechanism to center and clamp the pile, poles, pipe etc. in a fixed position within the apparatus to maximize the force of the strike and to assist in the more accurate positioning of the pile, pole, pipe etc. prior to and during driving.

BACKGROUND OF THE INVENTION

Free fall or drop type hammers have been used and are still being usedfor driving pile, poles, pipe etc. Hammer rams have historically beenlifted to free fall (drop height) by manual labor, winch and cablesystems, compressed air, hydraulic fluid under pressure and theexplosive force of diesel fuel combustion. All of these systems havebeen and are still employed to raise a ram to a predetermined height forrelease into free fall or drop; the pull of gravity in relation to rammass releases a driving force upon impact with the object (pile, poles,pipe etc.) that is being driven.

The above mentioned methods of raising a ram are energy intensive andrequire a heavy supporting structure. The Chain Drive ReciprocatingHammer with automatic work piece centering and clamping has a greatlyreduced energy requirement to raise a given ram weight to a given freefall or drop height. The Chain Drive System also allows for a reducedoverall hammer height.

Conventional pile, pole, pipe etc. driving systems require ancillarywork piece positioning systems i.e.: leads, pull ropes, etc. toaccurately position and hold the driving hammer and work piece in alinear configuration perpendicular to the substrate i.e.: ground, beachetc. that the driven piece i.e.: pile, pole, pipe etc. is being drivenin to. The Chain Drive Reciprocating Hammer with work piece centeringand clamping eliminates or greatly lessons the need for afore mentionedancillary work piece positioning systems i.e.: leads, pull ropes, etc.Furthermore, it maximizes the force of the ram impact to the work pieceby ensuring and maintaining centering between the ram and the workpiece. The relationship established and maintained by the automatic workpiece input centering and clamping mechanism does not allow any energy(force of impact between ram and work piece) to be diverted via a sideor glancing blow. Pile driving hammers with conventional bells, bonnets,etc. cannot adjust their internal inlet diameter to the multitude ofoutside diameters found with work output such as wooden pile or poles.Although wooden pile or poles have a consistent overall length theiroutside diameters at the driven end can, and most often vary with eachindividual pile or pole.

SUMMARY OF THE INVENTION

The present invention is premised on the realization that energyefficient driving of piles, poles, pipe etc. can best be accomplishedwith a chain ram lifting system and mechanism to hold the work piecei.e.: pile, pole, pipe etc. securely and correctly for maximum energy(force of ram impact) transfer. The present invention does not requirethe mass (weight) of an: air cylinder, hydraulic cylinder ordiesel/fuel/combustion mechanism to raise the ram to an adequate drop(free fall) height. A light weight air, electric or hydraulic motor isused to rotate a simple roller chain that has one or more grab links.The grab link meshes with the ram and as the roller chain travels inboth a linear and vertical path, the ram is lifted to a pre-selecteddrop (free fall) height and released.

The present invention also incorporates a mechanism that upon activationcenters the work piece i.e.: pile, pole, pipe etc. by being centered andsecurely clamped, becomes in effect and extension of the hammer. Thehammer/work piece unit is now easily maneuvered to the desired point ofsubstrate i.e.: ground, beach etc. and driven (hammered) to an adequatedepth for proper load bearing. Also, due to the centered condition ofthe work piece, the energy of the ram blow (strike, etc.) is bettertransferred from the ram to the work piece. This reduces energy losscaused by a side or glancing blow from the ram to the work piece.

BRIEF DESCRIPTION OF THE DRAWING

The figure is a diagrammatic depiction of the apparatus showing thechain drive and the automatic centering and clamping mechanism. It showshow the work input is held securely and maintains a center linerelationship with the ram.

DETAILED DESCRIPTION

As shown in the drawing, the work piece 2 i.e.: pile, pole, pipe etc. ispositioned within the throat 1 of the self centering and clamping bell(bonnet) 3. The centering/clamping cylinders 10 are activated causingthe articulated links 9 to move towards and engage the work piece 2while automatically by virtue of design centering the work piece to 2 tothe bell (bonnet) 3. Adequate force is applied by the articulating links9 to ensure adequate gripping of the work piece 2 so accuratemaneuvering and positioning of the work piece 2 can take place. Once thework piece 2 is correctly clamped and centered and is secure so as tocomprise an effective hammer/work piece unit properly positioned inrelation to the ground, beach etc. hammering/driving can now commence.Power (air, electricity, hydraulics, etc.) to rotate the driven sprocket3 is applied. The driven sprocket 3 rotates with torque causing theroller chain 4 to move linearly and parallel with the ram guide tube 11in a direction opposite to the pull of gravity. The roller chain 4 hasone or more lift/grab links 7 that mesh with the ram 6. As the rollerchain 4 with the ram 6 in tow travels linearly between the drivensprocket 3 and the tandem release sprocket assembly 8, the ram is raisedto a release point pre-selected by the location of the tandem releasesprocket assembly 8.

Note: The tandem release sprocket assembly's position can be adjusted upor down on the work side that grabs the ram so that the ram freefall/drop length can be matched to the requirement of the specifichammer/driving job.

The roller chain 4 with the ram 6 in tow will follow a vertical pathparallel with the ram guide tube 11 to a pre-selected release point asdetermined by the position where the roller chain 4 rotates around thetandem release sprocket assembly 8. Upon reaching this release point,the grab chain link will un-mesh with the ram 6. The ram will now freefall (drop) and apply energy (impact force) to the work piece 2 thushammering (driving) it.

1. An apparatus for driving pile, pole, pipe etc. that uses a chainsystem for lifting the ram to a pre selected drop point.
 2. An apparatusutilizing a mechanism for adjusting the drop point of a ram in a pile,pole, pipe etc. driving application with a hammer using a moveable andadjustable tandem set of sprockets.
 3. An apparatus utilizing amechanism for centering and clamping a pile, pole, pipe etc. in thecenter bell (bonnet) of a pile driving hammer. Said mechanismincorporates an apparatus that increases or decreases the area withinthe bell (bonnet). Said mechanism adjusts automatically upon activation,the inside diameter of the bell (bonnet) to the outside diameter of thework piece input, while simultaneously maintaining a positive centerline relationship between the ram and the work piece. This ensures thatmaximum energy transfer takes place from the falling ram mass uponimpact to the work piece i.e. pile, pole, pipe etc.